The effect of airborne dust on the stabilization of the early Mars atmosphere against atmospheric collapse

The stability of the early Martian atmosphere against collapse is fundamentally important for understanding the evolution of Mars’ atmosphere and surface throughout its history. A clear, thick (~80 mb) carbon dioxide atmosphere early in Mars’ history is not stable against collapsing into permanent polar caps. However, the presence of airborne dust may provide a mechanism to stave off atmospheric collapse. We are in the initial stages of an investigation targeted on developing a fundamental understanding of the role of the dust cycle in determining the ability of massive early atmospheres to be maintained for substantial periods of geologic time. We utilize the NASA Ames Mars General Circulation Model (MGCM) to explore early thick atmospheres with a range of dust loadings and polar cap albedos to investigate the effectiveness of increasing the atmospheric dust load on limiting atmospheric collapse. Early results indicate that increasing the dust content of the atmosphere slows the rate of atmospheric collapse, and that the polar cap albedo is a critical parameter in determining the stability of the atmosphere.